Lightweight conveyor roller

Abstract

A roller made lighter through the use of lightening elements. The inventive roller, with its lightening element(s), is lighter yet maintains its overall dimensions, is strong and durable enough to withstand the rigors of the transportation industry and/or is cost effective to produce and maintain. The lightweight roller may be part of a system having at least one operable roller unit, each roller unit having a roller, cylindrical in shape having a length and a diameter, and a center aperture extending through the length of the roller, an axel/shaft having a diameter sized to rotatably fit within the central aperture of the roller, the shaft further having a retention mechanism located upon the shaft ends and an elongate “U” shaped roller rack, the roller rack sized to extend the length of the roller and having a pair of upwardly extending arms located adjacent the ends of the roller, each arm end having an aperture sized to receive the respective shaft end and locate the shaft with the roller in a fixed location. The roller system has at least one roller, preferably more or all of the rollers, having internal and/or external lightening elements.

What is claimed: 
     
       1. A conveyor roller comprising:
 a) a one-piece integral body having a cylindrical shape, the entirety of the body being formed solely out of a single piece of polymeric material, said body having a length extending from a first outermost end to a second outermost end and a diameter, the first outermost end of the body defined by a first outwardly protruding portion that protrudes longitudinally from a first intermediate end to the first outermost end thereby defining a first exterior shoulder between the first outermost end and the first intermediate end, the second outermost end of the body defined by a second outwardly protruding portion that protrudes longitudinally from a second intermediate end to the second outermost end thereby defining a second exterior shoulder between the second outermost end and the second intermediate end; 
 b) said body defining an aperture extending longitudinally along and through the center of said body from the first outermost end to the second outermost end, the aperture sized to rotatably receive an axle therethrough; 
 c) said body also defining a plurality of internal bores that extend longitudinally parallel to the aperture extending through the center of said body, the plurality of internal bores each radially spaced evenly about the aperture extending through the center of said body, the plurality of internal bores extending through at least one of the first intermediate end and the second intermediate end of said body; and 
 (d) a cover for closing at least one of the first intermediate end and the second intermediate end of said body through which the plurality of internal bores extend through; 
 (e) wherein the aperture extending longitudinally through the center of the body defines at least a portion of a self-lubricating bushing that is formed by the one-piece integral body. 
 
     
     
       2. The roller of  claim 1 , wherein a shape of each of the internal bores is selected from a group consisting of tubular, ovular, elliptical, and spherical. 
     
     
       3. The roller of  claim 1 , wherein a polymer of the single piece of polymeric material is selected from a group consisting of polysulfone, nylon, polycarbonate, polyetherimide, polyetherketone, polyphenylene sulfide, polyvinylidene fluoride, and acetal copolymer. 
     
     
       4. The roller of  claim 1 , wherein a polymer of the single piece of polymeric material is acetal copolymer. 
     
     
       5. The roller of  claim 1 , wherein the plurality of internal bores reduces the weight of the roller by at least about 0.018 oz. compared to the weight of the roller without the plurality of internal bores. 
     
     
       6. The roller of  claim 1 , wherein the plurality of internal bores reduces the weight of the roller by at least about 0.035 oz. compared to the weight of the roller without the plurality of internal bores. 
     
     
       7. The roller of  claim 1 , wherein the roller has a compressibility strength of at least 20 psi. 
     
     
       8. The roller of  claim 1 , wherein the roller has an impact strength of at least 0.5 (foot lbs.)/inch. 
     
     
       9. The roller of  claim 1 , wherein the plurality of internal bores are filled with air. 
     
     
       10. A conveyor roller system comprising:
 a) at least one conveyor roller including a one-piece integral body having a cylindrical shape, the entirety of the body being formed solely out of a single piece of polymeric material, said body having a length extending from a first outermost end to a second outermost end and a diameter, the first outermost end of the body defined by a first outwardly protruding portion that protrudes longitudinally from a first intermediate end to the first outermost end thereby defining a first exterior shoulder between the first outermost end and the first intermediate end, the second outermost end of the body defined by a second outwardly protruding portion that protrudes longitudinally from a second intermediate end to the second outermost end thereby defining a second exterior shoulder between the second outermost end and the second intermediate end, said body defining an aperture extending longitudinally along and through the center of said body from the first outermost end to the second outermost end, the aperture sized to rotatably receive an axle therethrough, and said body also defining a plurality of internal bores that extend longitudinally parallel to the aperture extending through the center of said body, the plurality of internal bores each radially spaced evenly about the aperture extending through the center of said body, the plurality of internal bores extending through at least one of the first intermediate end and the second intermediate end of said body, wherein a cover closes at least one of the first intermediate end and the second intermediate end of said body through which the plurality of internal bores extend through and wherein the aperture extending longitudinally through the center of the body defines at least a portion of a self-lubricating bushing that is formed by the one-piece integral body; 
 b) an axel having a diameter sized to rotatably fit within the aperture extending through the center of said body of the roller, the axel further having a retention mechanism located upon axel ends; and 
 c) an elongate “U” shaped roller rack, the roller rack sized to extend the length of the roller and having a pair of upwardly extending arms located adjacent the first and second outermost ends of the roller, each arm end having an arm aperture sized to receive a respective axel end. 
 
     
     
       11. The roller system of  claim 10 , wherein a polymer of the single piece of polymeric material is selected from a group consisting of polysulfone, nylon, polycarbonate, polyetherimide, polyetherketone, polyphenylene sulfide, polyvinylidene fluoride, and acetal copolymer. 
     
     
       12. The roller system of  claim 10 , wherein a polymer of the single piece of polymeric material is acetal copolymer.